diff --git a/src/shared/compatibility.js b/src/shared/compatibility.js
index 6e3f191e8..4822755cd 100644
--- a/src/shared/compatibility.js
+++ b/src/shared/compatibility.js
@@ -25,10 +25,8 @@ var globalScope = require('./global_scope');
 
 var userAgent = (typeof navigator !== 'undefined' && navigator.userAgent) || '';
 var isAndroid = /Android/.test(userAgent);
-var isAndroidPre3 = /Android\s[0-2][^\d]/.test(userAgent);
 var isAndroidPre5 = /Android\s[0-4][^\d]/.test(userAgent);
 var isChrome = userAgent.indexOf('Chrom') >= 0;
-var isChromeWithRangeBug = /Chrome\/(39|40)\./.test(userAgent);
 var isIOSChrome = userAgent.indexOf('CriOS') >= 0;
 var isIE = userAgent.indexOf('Trident') >= 0;
 var isIOS = /\b(iPad|iPhone|iPod)(?=;)/.test(userAgent);
@@ -470,38 +468,17 @@ PDFJS.compatibilityChecked = true;
   PDFJS.locale = navigator.userLanguage || 'en-US';
 })();
 
-// Support: Safari 6.0+, Android<3.0, Chrome 39/40, iOS
+// Support: Safari 6.0+, iOS
 (function checkRangeRequests() {
   // Safari has issues with cached range requests see:
   // https://github.com/mozilla/pdf.js/issues/3260
   // Last tested with version 6.0.4.
-
-  // Older versions of Android (pre 3.0) has issues with range requests, see:
-  // https://github.com/mozilla/pdf.js/issues/3381.
-  // Make sure that we only match webkit-based Android browsers,
-  // since Firefox/Fennec works as expected.
-
-  // Range requests are broken in Chrome 39 and 40, https://crbug.com/442318
-  if (isSafari || isAndroidPre3 || isChromeWithRangeBug || isIOS) {
+  if (isSafari || isIOS) {
     PDFJS.disableRange = true;
     PDFJS.disableStream = true;
   }
 })();
 
-// Check if the browser supports manipulation of the history.
-// Support: IE<10, Android<4.2
-(function checkHistoryManipulation() {
-  if (!hasDOM) {
-    return;
-  }
-  // Android 2.x has so buggy pushState support that it was removed in
-  // Android 3.0 and restored as late as in Android 4.2.
-  // Support: Android 2.x
-  if (!history.pushState || isAndroidPre3) {
-    PDFJS.disableHistory = true;
-  }
-})();
-
 // Support: IE<11, Chrome<21, Android<4.4, Safari<6
 (function checkSetPresenceInImageData() {
   if (!hasDOM) {
diff --git a/web/app.js b/web/app.js
index bf2226b87..0dd5f1f54 100644
--- a/web/app.js
+++ b/web/app.js
@@ -1525,10 +1525,6 @@ function webViewerInitialized() {
     if ('verbosity' in hashParams) {
       PDFJS.verbosity = hashParams['verbosity'] | 0;
     }
-    if ('ignorecurrentpositiononzoom' in hashParams) {
-      PDFJS.ignoreCurrentPositionOnZoom =
-        (hashParams['ignorecurrentpositiononzoom'] === 'true');
-    }
     if (typeof PDFJSDev === 'undefined' || !PDFJSDev.test('PRODUCTION')) {
       if ('disablebcmaps' in hashParams && hashParams['disablebcmaps']) {
         PDFJS.cMapUrl = '../external/cmaps/';
diff --git a/web/base_viewer.js b/web/base_viewer.js
index bc953977e..521b193a7 100644
--- a/web/base_viewer.js
+++ b/web/base_viewer.js
@@ -505,7 +505,7 @@ class BaseViewer {
 
     if (!noScroll) {
       let page = this._currentPageNumber, dest;
-      if (this._location && !PDFJS.ignoreCurrentPositionOnZoom &&
+      if (this._location &&
           !(this.isInPresentationMode || this.isChangingPresentationMode)) {
         page = this._location.pageNumber;
         dest = [null, { name: 'XYZ', }, this._location.left,
diff --git a/web/ui_utils.js b/web/ui_utils.js
index dc762dfeb..455309b50 100644
--- a/web/ui_utils.js
+++ b/web/ui_utils.js
@@ -102,12 +102,6 @@ PDFJS.disableHistory = (PDFJS.disableHistory === undefined ?
 PDFJS.disableTextLayer = (PDFJS.disableTextLayer === undefined ?
                           false : PDFJS.disableTextLayer);
 
-/**
- * Disables maintaining the current position in the document when zooming.
- */
-PDFJS.ignoreCurrentPositionOnZoom = (PDFJS.ignoreCurrentPositionOnZoom ===
-  undefined ? false : PDFJS.ignoreCurrentPositionOnZoom);
-
 if (typeof PDFJSDev === 'undefined' ||
     !PDFJSDev.test('FIREFOX || MOZCENTRAL')) {
   /**